Side-wall sampling device for well bores



Aug. 1%, 1%43. P NCER SIDE-WALL SAMPLING DEVICE FOR WELL BORES 2 Sheets-Sheet 1 Filed June 2, 1941 aim INVENTOR nan 9 Ezra! Aug. 10,1943. L. SPENCER SIDE-WALL SAMPLING DEVICE FOR WELL BORES Filed June 2, 1941 2 Sheets-Sheet 2' w w w ma v lim a INVENTOR Q Patented Au 10, 1943 SIDE-WALL SAMPLING DEVICE FOR WELL BORES Lloyd Spencer, Los Amgeles, Calif., assignor to Lane-Wells Company, Los Angeles, Calif, a

corporation of Delaware Application June 2, 1941, Serial No. 396,281

(Ci. 255=-l.4)

11 Claims.

My invention relates to side-wall sampling devices for well bores, that is, to devices which are lowered within an uncased well bore and caused to extract a sample of the surrounding formation. Among the objects of my invention are:

First, to provide a sampling device which is adapted to be suspended from a cable;

Second, to provide a sampling device which is so arranged that little or no strain is applied to the cable during the course of urging the sample-taking elements into the formation or retracting them from the formation;

Third, to provide a sampling device whereby a plurality of sampling units may be operated independently and in sequence so that samples,

may be taken at a number of preselected levels; Fourth, to provide a sampling device wherein sampling elements are caused'to move, with respect to the body of the sampling device, from an initially downwardly directed position and during its movement to engage and penetrate the formation; Fifth, to provide a sampling device which, by reason of the fact that the sampling elements occupy upright positions after obtaining their formation samples, retain their samples even though the formation should be soft and would otherwise fall from the sampling elements;

Sixth, to provide a sampling device which, by reason of the fact that the sampling elements move in an upward are as distinguished from a downward arc, materially reduces the possibility of sticking or anchoring the sampling device in the well bore; for should the formation be too hard for the sampling element to penetrate, the sampling element is restrained by the formation to a downwardly inclined position which does not interfere with upward movement of the sampling device and therefore permits withdrawal 'from the well bore;

Seventh, to provide a sampling device which, should the sampling unit be prevented from operation by reason of a hard formation, may be operated to release the driving force behind the sampling unit so that the device may be easily moved upwardly in the well bore to a new location and again operated, or be withdrawn; and

Eighth, to provide a sampling device which may be controlled electrically through its supporting cable.

With the above and other objects in view, as may appear hereinafter, reference is directed to the accompanying drawings, in which:

Figure l is an elevational view of the side-wall ing a sample from formation confronting a well bore;

Figure 2 is an enlarged fragmentary sectional view thereof viewed in a plane parallel to Figure 1, showing the initial, intermediate and final positions taken by the sampling unit;

Figures 3, 4 and are transverse sectiona views through 3-3, 44 and 5-5, respectively, of Figure 2; 1

Figure 6 is a longitudinal sectional ;view in the same plane as Figure 2 and continuing upwardly therefrom; and v Figures '7, 8, 9 and 10 are transverse sectional views thereof through 1-1, 88, 99 and sampling device shown in the process of 'extractill-Ill respectively.

With reference particularly to Figures 2 and 5, my side-wall sampler comprises two side plates l which are complementary and define between them a longitudinal channel ,2, at the base or' inner end of which is a longitudinallyextending guide slot 3 which is necked down or constricted in cross section at its juncture along the channel 2. Along the base side of the guide slot 3 the side plates abut or bear against each other. The side plates are connected bya series of journal pins 4 which extend across the channel 2. Each journal pin receives a segmental gear 5. The segmental gears are adapted to be rotated onehalf turn in sequence by a rack 6 which is adapted to travel downwardly in the guide slot 3; the rack being held in the guide slot by reason of the constriction between the guide slot and the channel 2, as shown in Figure 5. v

Each segmental gear receives a sampling tube l which extends radially from the axis of its journal pin and segmental gear and is adapted to turn in the plane of the channel 2. Initially each sampling tube is directed downwardly from its segmental gear and is entirely within the channel 2. The entering end of the rack 6 is provided with a rudimentary axial extension 8 from which teeth have been removed, that is, its surface is equal to the base ends of the teeth. A complementary elevated portion 9 is provided at the leading portion of the segmental gear teeth. The extension 8 and elevated portion 9 facilitate initial engagement of the rack 6 with the segmental gears 5.

The rack 6 is attached to or made integral with a push r'od lil which continues upwardly from the rack. The push rod has a cross section equal to the rack, including the teeth, that is, one side is flush with the extremities of the rack teeth. The trailing end of the segmental teeth of each segmental gear is reduced in radius to that of the base ends of the gear teeth, as indicated by H, so that after the segmental gear has been turned by the rack 6 the push rod II] which follows may clear the segmental gear. This also serves the purpose of locking the segmental gear against return movement once the [rack has passed beyond the gear, as shown in Figure 2. During travel of each segmental gear its sampling tube 7 moves arcuately from an initial position such as indicated by A in Figure 2, to an intermediate position indicated by B and completes its movement when it assumes the final position indicated by C in Figure 2.

The upper ends of the side plates l are joined to a body member |2 by means of bolts I3 which extend diametrically through a tongue |4 adapted to fit in the upper end of the channel 2. The body member is cylindrical and is provided with a push rod passage which is oifset with respect to the axis of the body member and in alignment with the guide slot 3 defined by the side plates. The body member is also provided with a centrally disposed ejector mandrel socket l6, one side wall of which intersects the push rod passage |5.

Reference is now directed to Figure 6: The upper end of the body member I2 is connected to a push rod magazine H which is tubular and has a chamber concentric with the ejector mandrel socket but'of suflicient diameter to embrace the push rod passage I5. The push rod magazine I1 is preferably secured to the body member |2 by radial pins l8. The socket I6 is adapted to receive an ejector mandrel l9 which is provided at its upper end with a radially directed ejector lug 20. The ejector lug is adapted to align with the push rod passage IS. A keyway 2| is provided longitudinally in the ejector mandrel and a; key 22 fits therein; the key 22 may be an extension of one of the pins I8, as

shown in Figures 6 and 10. The push rod magazine I1 is provided with a longitudinally extending rib 23, one radial side thereof aligning with the radial side of the push rod passage I5. When the rack 6 is in its initial position, that is, about to engage the uppermost segmental gear in Figure 2, the first push rod It! extends upwardly into the magazine along the side of the rib 23. Within the magazine, arranged around the mandrel I9, are additional push rods Illa. Adjacent the rib 23, but on opposite sides thereof from the push rod I0, is a longitudinally extending feeder bar 24. A pair of springs 25 and 26 arranged in channels 21 and 28 at the bottom and top portions, respectively, of the push rod magazine extend around the push rod. One end of each spring is anchored into an end of the feeder bar 24 and the other end into the rib 23. The springs are arranged to exert a. torque on the feeder bar, urging the push rod counterclockwise as viewed in Figure 8. The ejector mandrel l9 reciprocates from an upper position in which the ejector lug is above the push rod into a position partially within the ejectormandrel socket 16. When the ejector lug clears the push bars contained in the magazine the springs and 26 urge a new push bar into alignment with the preceding one, so as to be forced downwardly at the next downward movement of the ejector mandrel.

The upper end of the push rod magazine I! is screw-threaded to a sleeve 29 which in turn is joined to a cylinder head 30; A piston rod 3| extends downwardly through the cylinder head 30 and a packing gland 32 provided therein. The piston rod is secured to the upper end of the ejector mandrel I9. I

Secured within the sleeve 29.above the push rod magazine I1 is a guide block 33 having a hole 34 therethrough shaped to clear the cjcctor mandrel and ejector lug. Fitted within the hole 34 is a stop plug 35 throughwhich the piston rod 3| extends. limit downward movement of the stop 35 and the stop is yieldably-held in a downward position by means of aspring 36 provided around the piston rod 3|. The stop 35 coacts with the ejector lug to prevent movement of a new push rod into place before the ejector lug has returned to its upper position. The cylinder head 30 is connected to a ram cylinder 31 shown diagrammatically in Figure l. The ram cylinder 31 contains a piston (not shown) connected with the piston rod and is connected at its upper end to a driving mechanism housing 38 which contains suitable mechanism, such as an electric motor and pump. If an electric motor prime mover is used the housing 38 may be connected to a cable head 39 which in turn is connected to a cable 40 having a conductor core.

It is also contemplated that in place of a piston and cylinder arrangement a screw jack may be used to operate the rod 3|. The precise form of construction of the driving means for the rod 3| i not a part of the present application, except insofar as means are provided to reciprocate the rod 3| a suflicient number of times to permit the ejector bar to engage and urge the several push rods into the guide slot 3 and at the same time develop a suflicientforce to urge the sampling tubes 1, one at a time, into the formation.

Along the rear side of the side plates opposite the channel 2, the side plates are provided with a shoe 4| which overlaps the two side plates and forms a dovetailed connection 42 therewith, so that the shoe may move upwardlyand downwardly with respect to-the side plates but is held in position. The side plates, together with the shoe, are substantially cylindrical in cross section, with the exception that the shoe may project slightly beyond the normal diameter of the side plates, as shown in Figures 3, 4 and 5. The shoe 4| extends upwardly along one side of the body member and this side of the body member is likewise dovetailed to conform to the sho 4|. Around the body member 2| is slidably mounted a collar 43 which rests upon the upper end of the shoe 4|. A spring 44 engages the collar 43 and is wrapped around the upper portion of the body member I2, as well as the push rod magazine IT. The upper end of the coil spring 44 bears against a shoulder 45 provided near the upper end of the push rod magazine. The shoe normally occupies a lower position, but in the course of extracting a sample the shoe moves upwardly with respect to the side plates I or, more correctly, the shoe member tends to remain fixed against the side wall of the well bore while the side plates I move downwardly.

ward by any suitable means the ejector lug 20 of the ejector mandrel I9 pushes downward on the upper end of the first push rod l0. Movement of the rack 6 past the uppermost segmental gear causes the segmental gear to rotate from the position A through position B to a final position C,

Shoulders in the hole 34 shown in Figure 2. when the sampling tube has been moved part way between the positions A and B it engages the side wall of the well bore, forcing the shoe 4| against the opposite side of the well bore. Continued rotation of the sampling tube forces its extremity, which is sharpened, into the formation. The tendency is for the extremity of the sampletube to fulcrum at its point of engagement with the formation; consequently, the entire sampling device tends to move downward in the well bore. This is permitted by slacking off the cable which supports the tool. Continued movement from position A through position B forces the sample tube into the formation and as the movement continues from position B to position the sample tube is withdrawn from the formation. After the rack has completed its engagement with the segmental gear, the gear is locked against return movement and the sample is held in within the sampling tube.

It is preferred to employ as a prime mover an electrical motor or device so that by noting the current being drawn by the motor the operation of the sampling device may be observed at the surface; that is, during the actual sampling operation the power required reaches a maximum and then returns to a minimum as the sampling element or sampling tube moves back into the channel 2. By providing a small amount of free travel before the rack engages the second or following segmental gear, the operator may from the surface stop the operation of the sampling device and raise it in the well-bore to a new location. By providing a magazine and push rod of sumcient length to operate two or more sampling units, two or more samples may be taken for each reciprocation of the piston rod. After the first push rod hasbeen forced entirely from the magazine the ejector lug 2G is raised to its upper position, permitting another push rod 50a to move into alignment with the original push rod ill and an upright position rack 6. Downward movement of the ejector lug is repeated and the segmental gears next in order are actuated.

t should be noted that should the sample tube encounter a hard formation which would require more force than available through the rack 6 it will occupy some position between A and B; that is, the extremity of the sample tube will be directed downwardly and outwardly. By releasing the pressure on the rack the entire tool may be easily raised and the tool either removed entirely or merely raised to a point where the operator believes the formation to be softer. No undue strain is placed on the cabl to accomplish this and there is no danger of the tool becoming stuck in the well. As soon as the tool-has been moved to a new position the operation of the rack may be continued. It should be noted that if sufiicient force is developed to move the sampling tube to position B that sufiiclent force is also available nel; and means for driving said sampling tube from its initial to its final position.

3. A side-wall sampling apparatus comprising: a supporting structure defining a longitudinal channel; a plurality of initially depending sampling tubes journaled in sequence in said channel; a drive means movable along said channel and operatively connected with each of said sampling tubes in sequence to move said tubes arcuately through a lateral position to an upright position.

4. A side-wall sampling apparatus comprising:

a supporting structure defining a longitudinal channel; a drive means including an operating element adapted to engage said sampling tubes in sequence and move said samplingtubes from an initially depending position through a lateral position to an upright position; a sectional push rod for actuating said operating element; a magazine for holding the sections of said push rod; reciprocating means for ejecting said push rod section from the magazine; and means for feeding said push rod sections into position for ejection.

5. A. side-Wall sampling apparatus comprising: a supporting structure adapted to be suspended from a cable, and incorporating relatively longitudinal moving elements; a plurality of samwherein said supporting structure is movable bodto move it to position C, for the simple reason that less force is required to withdraw the tube than is required to force it into the formation."

Various changes and alternate arrangements may be made within the scope of the appended claims, in which it is my intention to claim all novelty inherent in the invention as broadly as the prior art permits.

Iclaim:

1. A side-wall sampling apparatus comprising: a supporting structure; a plurality of sampling tubes carried thereby; means journaling said sampling tubes; and means for. rotating said samily, simultaneously with relative longitudinal movement of said elements, to permit fulcruming of said sample tubes about their points of engagement with the formation.

7. A side-wall sampling apparatus comprising: a supporting structure defining a longitudinal channel; a sampling tube journaled in said channel and movable arcuately from an initially depending position laterally outward into engagement with formation surrounding the sampler and continuing to a final upright position within said channel; means movable longitudinally in said supporting structure for driving said sampling tube; and yieldable means for suspending said supporting structure to permit bodily movement of said supporting structure and drive means whereby said sampling tube may fulcrum about its point of contact with the formation.

8. A side-wall sampling apparatus comprising: a supporting structure defining a longitudinal channel; a sampling tube journaled in said channel and movable arcuately from an initially depending position laterally outward intoengagement with formation surrounding the sampler and continuing to a final upright position within said channel; means movable longitudinally in said supporting structure for driving said sampling tube; yieldable means for suspending'said' journaled in said channel for successive engagement by said rack; and sampling elements connected with said gear elements and driven thereby into contact with the surrounding walls of a bore hole.

10. A construction, as set forth in claim 9,

wherein the push bar is sectional and which includes: a magazine for. said push bar sections; and means for feeding said push bars into said channel to urge said rack therealong.

11. A side-wall sampling apparatus comprIs ing: a body structure defining a longitudinal channel; a shoe sliclably mounted on said body structure at the side opposite from said channel; a plurality of sampling elements in said channel and adapted to move arcuately in the plane thereof from a position within the channel to an extended position in engagement with a wall of a surrounding bore hole, thereby urging said shoe against the opposite wall of the bore hole; and means movable relative to said body structure-for actuating said sampling elements.

LLOYD SPENCER. 

